Air-brake attachment.



PATENTBD SEPT. 18, 1906.

J. B. O'DONNBLL.

AIR BRAKE ATTACHMENT. APPLICATION FILED H0120; 1905.

N VE N TOR fim'esfl 02022 72 eZZ v WITNESSES: frm

, ATTORNEYS UNITED STATES PATENT OFFICE.

AIR-BRAKE ATTACHIVIIENT.

Specification of Letters Patent.

Patented Sept. 18, 1906.

Application filed November 20, 1905. $erial No. 288,190-

To all whom it may concern.-

Be it known that I, JAMES BENEDICT ODONNELL, a citizen of the United States, and a resident of Freeland, in the county of Luzerne and State of Pennsylvania, have invented a new and Improved Air-Brake Attachment, of which the following is a full, clear, and exact description.

The object of my invention is to provide means by which the engineer on a train equipped with the automatic air-brake system may be given full control of the triple exhausts independently of and notwithstanding the usual retaining-valves. This end I attain by fitting to the triple exhaust a valve closing by the brake-cylinder pressure and commanding a vent to the atmosphere, which valve is under the control of the engineer through the medium of a fluid-pressure device actuated by the train-line pressure.

The invention resides in certain special features of construction and combinations of parts, which will be fully set forth hereinafter, and particularly pointed out in the claim.

Reference is had to the accompanying drawings, which illustrate, as an example, the preferred form of my invention, and in which Figure 1 is a view showing the invention in place in the automatic air-brake system, and Fig. 2 is a sectional view showing the secondary retaining-valve and its operating device.

In Fig. 1, 0, indicates the train-line, I) the auxiliary, c the brake-cylinder, (Z the triple valve, 6 the retaining-valve connection, and

f the retaining-valve, all of which may be of the usual or any desired form.

From the retaining-valve pipe 6 or from some other part in communication with the triple exhaust passes a branch g, which leads into a casing h. This casing has a vent to the atmosphere commanded by a valve 'L, and this valve is yieldingly seated by a spring 76. The stem Z of the valve projects through the opening in the lower end of the casing beyond the same.

Communicating with the train-line a is a branch m, which may, if desired, be fitted with a cock m, as shown. This cock, however, is normally open, and the pipe m leads to a casing 0, in which is arranged a piston, diaphragm, or other equivalent part p, subject on its lower side to the train-line pressure.

q indicates a spring which is designed to move the piston p down against the normal train-line pressure, but which upon abnormally raising the train-line pressure gives way to the same and permits the piston to rise. A rod 1* in connection with the piston not only guides the same in its movement, but projects beyond the case 0 in such position as to strike the stem Z upon the movement of the piston 10 against the spring q.

In the use of the invention should the retaining-valve f be open the brake system will operate unaffected by my improvements. When said valve f is closed to retain the brake-cylinder pressure, a normal trainline increasesay to ninety poundswill not affect the spring 1 and piston 17 and the triple exhaust will remain closed. If, however, the engineer desires completely to bleed the brake-cylinders, notwithstanding that the retaining-valves f are closed, he has only to raise the train-line pressure above the normalsay, to ninety-five poundswhereupon the piston p will be lifted and its rod 1' will engage the stem Z of the valve t, opening said valve and permitting the brake-cylinder air to pass by the pi e g and case it into the atmosphere. Usual y when the retainingvalves are'closed by the train crew the engineer has no control over them and cannot bleed the brake-cylinders. By means of my invention, however, through the simple expedient of raising the train-line pressure slightly above the normal the triple exhausts may be open independently of the position of the usual retaining-valves.

Having thus described my invention, I claim as new and desire to secure by Letters Patent In auxiliary valves for air-brake systems, the combination of the casing having an exhaust-port and adapted for connection with the exhaust of the brake-cylinder, a springactuated piston within the casing normally closing the exhaust-port and provided with a rod extending without the casing, a casing for connection with the train-pipe, a piston movable within the casing, and a spring for supporting the piston against the normal pressure'of the air in the train-pipe, said piston having a rod extending Without the easing and arranged to contact with the rod of two subscribing witnesses. the first piston whereby to operate said pis- JAMES BENEDICT ODONNELL. 5 ton to 0 en the exhaust-port upon a prede- Witnesses:

termine increase of pressure in the train- C. 0. Simon,

pipe. A.' O. VAN AKEN.

In testimony whereof I have [signed my name to this specification in the presence of 

